Safety device for cinematographic apparatus



P. S. GAURIAT.

SAFETY DEVICE FOR CINEMATOGRAPHIC APPARATUS.

APPLICATION FILED APR. 7. 1920.

1,367,958. Patented Feb. 8,1921.

Inventor.

UNITED STATES PATENT OFFICE.

PIERRE SYLVAIN GAURIAT, OF TARIS, FRANCE, ASSIGNOR TO ETABLTSSEMENTS CONTINSOUZA SOCIETE ANONYME, OF PARIS, FRANCE, A FRENCH CORPO- SAFETY DEVICE FOR CINEMATOGRAPHIC APPARATUS.

Application filed April 7, 1920.

To all w /1 0m it may concern:

Be it known that I, PIERRE SYLVAIN GAU- nIAT, citizen ofthe French Republic, residing at Paris, Department of the Seine, 111 France, and having 1. 0. address 9 and 13 Rue des Envierges, in the said city, have invented certain new and useful Improvements in Safety Devices for Cinematographic Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will e11- able others skilled in the art to which it appertains to make and use the same.

This invention has for its object an arrangement which effects the stoppage of the apparatus in case a breakage of the film occurs caused by fire, wear, or accident due to a defectively cemented place, etc.

Certain apparatus are provided with automatic arresting devices, formed by a supplementary toothed drum, driven by thefilm, and driving any kind of device which effects by its action or non-working the operation or the stoppage of the apparatus; I

These devices have the disadvantage of increasing the surfaces in contact with or the friction on the film, with the result that increased wear of the film ensues. They also have the serious disadvantage of their safety being incomplete. Being placed on the apparatus, they cannot work in the case of an accident happening in the lower winder or between it and the apparatus (6. g. in the ease of a film badly attached or not fixed on the lower reel, an accidental breakage between the lower driving device and the winder, the film not being wound L up, etc.).

This consideration is the more important as the tendency is more and more to generalize the use of the protecting boxes for the reels of film. It is known in fact that when the fihn does not wind up on the lower reel. it continues to be driven by the apparatus, passes into the protecting box and is pushed out into this latter- Without the operator being aware of the fact, the apparatus continuing to work normally; even with the existing safety apparatus. It .is only when the protecting box is full of the unrolled film or when this latter gets in the apparatus itself, that the operator becomes aware of the accident which, in this case,- seriously damages the film.-

The device which forms the subjectmat- Specification of Letters Patent.

Patented Feb. 8, 1921.

Serial No. 371,949.

end of a film,..0r by an accidental breakage thereof, at whatever point it may be produced, the non-fixation of the film on the lower winder causing the device to work.

The absence of any supplementary parts in contact with the film, obviates increased wear thereof.

In the accompanying drawing is shown by way of example a constructional form of the subject matter of the invention.

Figure 1 is a section of the apparatus along a vertical plane passing through the axis of the lower reel.

Figs. 2 and 3 are detail views in elevation and in section of the driving pinion for the lower reel and of the rings which it carries.

Figs. 4 and 5 show respectively in elevation and in section a washer which particularly forms the subject matter of the inven tion and the function of which will be described hereafter.

A pinion 1 mounted on the spindle2 of the lower winder of the cinematographic apparatus is loose on this spindle. It carries mounted on a part of its circumference not provided with teeth a rin 3 of brass provided with a finger 4. he ring 3.is insulated from the pinion l by a ring of fiber 5 or any other insulating material.

A washer 6, likewise mounted on the spindle 2, and loose on this spindle, is constituted by an insulating material such as fiber, ebonlte, etc. It is integral with a ring '7 of brass, which is provided with a-finger 8 like the ring 3 (seeFigs. 4 and 5).

The two movable members 1 and 6 have respectively circular grooves 9 and 10 into which fits a spring 11, which bears with one of its ends on the pinion 1 and with the other end on the washer 6. This spring tends to force the two fingers 4 and 6 away from each other. On the two rings 3 and 7 rub two brushes 12 and 13 to each of which is connected a wire of the line which supplies the isshown the protecting box, at 20 the reel, at 21 the lower driving device of the apparatus.

The working of the apparatus will be easily understood from the foregoing description. lVhen the film is fixed normally in the apparatus, and on the spindle of the reel the driving pinion has imparted to it a. constant angular velocity. This velocity is always greater than that of the reel, since the film which is driven at a linear velocity which is always the. same by the lower driving device, winds up on itself and effects at each rotation of the reel an increase of \the winding core, the consequence of which is to necessitate a diminution of the angular velocity in order to preserve a constant circumferential velocity.

The result is a retardation of the reel on the driving pinion which brings about the operation of the friction device. At this moment the spring 11, the tension of which is determined in any suitable manner, is compressed and allows the fingers 4 and 8 to come into contact. The circuit which supplies the motor is closed and remains closed up to the moment when the friction device ceases to act. a breakage of the film occurs or at the end of a film. The reel which is no longer retarded in its rotation by the film then rotates at the same speed as the pinion l and permits the spring 11 to expand and force away from each other the fingers 4: and 8 whichplay the part of a switch thus bringing about the stoppage of the motor which drives the apparatus.

By means of the same switch device with the addition of a relay other movements might also be effected such as the operation of the starting rheostat of the motor, the illumination of the auditorium, the breaking of the electrical circuit which supplies the arc, etc. Claims:

1. In a safety device for motion picture apparatus of the electric motor-operated type, the combination with 'a film receiving reel and its-supporting shaft, of a frictional drive for. said shaft, comprising a pinion and a complementary member loosely mounted on said shaft, and a member keyed to the shaft cooperating with said complejmentary member, means for locking said pinion and complementary member together during the driving of the shaft and reel, electric contact members carried by the This happens when pinion and by its complementary member adapted to be engaged for closing the circuit to the motor during the normal driving of the reel and supporting shaft, and means for disengaging said contact members and breaking the circuit upon the release of the tension on said film.

2. In a safety device for motion picture apparatus of the electric motor'operated type, the combination with a film receiving reel and its supporting shaft, of a frictional drive for said shaft, comprising a pinion and a complementary disk loosely mounted on said shaft and a member keyed to the shaft cooperating with said complementary disk, compressible means positioned between 'the pinion and its complementary disk, allowing a limited, rotatable, relative movement of the pinion and disk, electric contact members carried by the pinion and its complementary disk, adapted to be engaged for closing the circuit to the motor during the normal driving of the reel and supporting shaft, at which time the compressible means is compressed, and said compressible means adapted to expand and disengage said contact members and thereby breaking said circuit upon the release of A the tension on the film.

3. In a safety device for motion picture apparatus of the electric motor-operated type, the combination with a film receiving reel and its supporting shaft, of a frictional drive for said shaft, comprising a pinion and a complementary disk loosely mounted on said shaft, and a disk keyed to the shaft cooperating with said complementary disk, means for maintaining said keyed disk in frictional engagement with said complementary disk, relatively short, curved, cutout, registering portions formed in the meeting faces of the pinion and complementary disk providing a recess therebetween, a coil spring positioned within said recess allowing a limited rotatable, relative movement of the pinion and disk, electric contact members carried by the pinion and by said disk, adapted to be engaged for closing the circuit to the motor during the normal driving of the reel and supporting shaft, at which time the spring is compressed, and said spring adapted to expand and disengage said contact members and thereby breaking said circuit upon the release of the tension on the film.

In testimony whereof I afiix my signature.

PIERRE SYLVAIN GAURIAT. 

